most_voted to false by default

db/migrate/20171019095042_add_most_voted_to_poll_question_answer.rb

@@ -1,5 +1,5 @@
 class AddMostVotedToPollQuestionAnswer < ActiveRecord::Migration
   def change
-    add_column :poll_question_answers, :most_voted, :boolean
+    add_column :poll_question_answers, :most_voted, :boolean, default: false
   end
 end

db/schema.rb

@@ -700,7 +700,7 @@ ActiveRecord::Schema.define(version: 20171019095042) do
     t.text    "description"
     t.integer "question_id"
     t.integer "given_order", default: 1
-    t.boolean "most_voted"
+    t.boolean "most_voted",  default: false
   end
 
   add_index "poll_question_answers", ["question_id"], name: "index_poll_question_answers_on_question_id", using: :btree